Adjustable tire building drum



July 21, 1936. H. c. BosTwlcK ADJUSTABLE TIRE BUILDING DRUM Filed Dec. 5, 1933 Patented July 2l, 1936 UNITED STATES PATENT OFFICE ADJUSTABLE 'rma BUILDmG DRUM Ohio Application December 5, 1933, Serial No. 700,987

` 1 Claim.

This invention relates to segmental', collapsible drums or chucks having a widthwise adjustment for building tire bands4 of different widths. Its objects are to reduce the number of sliding shouldered joints exposed on the periphery ofleach segment, to bring the joint to the marginal shoulder of the drum at the narrowest adjustvment so that there may be no intermediate shoulder at that adjustment, and to strengthen the drum structure.

Of the accompanying drawing, Fig. 1 is a side elevation of a tire-building drum embodying my improvements. i

Fig. 2 is an end elevation'as viewed from the right in Fig. l, partly broken away and in section.

Fig. 3 is a partial longitudinal section approximately on the lines 3 3 of Figs. 1 and 2.

In the drawing, lo is a central driving shaft' for supporting and rotating the drum or chuck I I, which has a segment-supporting spider I2 on said shaft, and a tubular control shaft I3 surrounding the driving shaft and having its end flange or collar connected by toggle links I 4, I5 with the four drum segments I6, I1 which are pivoted in pairs at opposite ends of said spider I2 and collectively constitute the drum shell. 'Ihe drum has an intermediate cylindrical portion and is formed at the side edges thereof with the usual depressed conical flanges I8 for supporting the margins of the under-beadplies of tire carcass fabric while being rolled down, and with radial bead-seating shoulders I9.

Each drum segment I6 or I1 includes a body or base segment 20 having inwardly-projecting hinge ears 2l turning on a pivot pin 22 carried by ears on one of the arms oi the spider I2, said segment having an outer surface substantially at transversely throughout its width, and an overlying pair of wing segments 25 and 26 formed with the marginal iianges I8 and bead seats I9, each being'secured upon the body seg-I ment by a pair of circumferentially spaced cap screws 21 having their heads under the body. segment. To provide a lateral adjustment for these wing segments to vary the width or axial length of the drum, the stem of each screw extends through a. laterally elongated slot 28 into either of a pair of threaded holes 29 in the wing segment, the partially extended adjustment being indicated by broken lines in Fig. 1 and the contracted or narrowest adjustment by full lines. The left-hand wing segment 25 is Wider than the segment 26 and at the' -narrowest adjustment the inner edges of the two substantially Ymeet each other.

Upon the wing segment 26 is mounted a thin shell segment 30 which overlies and is adapted to be supported by more or less of the width of the wing segment 25 to provide an axially continuous drum surface at all adjustments. Tov

' bead-seating shoulder to form a part of the latter when the drum has its narrowest or most-contracted adjustment as represented in full lines.

By thus attaching the shell member 30 to one of the adjustable wing segments instead of using a gap-shield xed upon a. central chuck rib, whose width is limited by the necessity of providing wide attaching portions upon the base segment to obtain the desired drum strength and range of adjustment, as has heretofore been customary, I reduce the liability to breaking off of the shield segments through the provision of a'wider and more secure attachment for said member, and eliminate one of the sliding joints on the drum surface whichhave heretofore collected the cement often used upon these drums to adhere the leading edge of the iirst fabric ply and which may gape when the drum has been considerably used. Since the bridging segment members 30 are attached to wing segments 26 adjustably secured upon the permanently mounted base segments 2l of the chuck by fastening screws 21 accessible from the inner sides of said base segments, circumferential alignment of both edges of each 'se'gment 26, including the members 30, with the edges of adjacent segments is readily obtainable on the chuck, without removal of any parts of the latter. Furthermore, if the edge of the member 30 is ex-f tended permanently to one drum shoulder and its other edge to the opposite shoulder at the narrowest adjustment, as shown in'this preferred embodiment, I avoid one oi' the stepsor intermediate `shoulders heretofore appearing on the cylindrical drum periphery, over'which the fabric must be rolled down, and also eliminate the other intermediate step or shoulder at said narrowest adjustment, so that the narrowest tire bands for which the drum is intended can be handled on a smooth-surfaced drum having no intermediate steps. The greater width of the wing segments I claim: A radially collapsibletire-building drum composed of segments each of which includes a bodyr or base segment having an outer surface substanber at all adjustments.

tially flat transversely throughout its width, a pair of wing members, one of which is narrower than the other, supported on said base segment and adapted substantially to meet at their adjacent edges, means for xediy securing said wing members to the base segment at different lateral adjustments to vary the width of the drum, and an outer member'xed to the narrower one of said wing members and overlying the otllr wing mem- HENRY C. mSTWICK. 

